Discrete light sources such as light-emitting diodes (LEDs) are an attractive alternative to incandescent light bulbs in illumination devices due to their higher efficiency, smaller form factor, longer lifetime, and enhanced mechanical robustness. LEDs may be grouped in clusters or arrays to provide a desired light output corresponding to design requirements and/or application specifications. Such multiple-LED groups combine the aforementioned advantages of LEDs with the larger light outputs of conventional light sources, enabling general-illumination applications. For example, when compared to incandescent lights, LED arrays may emit at comparable intensities with many times the efficiency and at a fraction of the operating costs.
However, lighting devices featuring arrays of interconnected LEDs do suffer from issues that plague all interconnected networks of devices—when a single device fails, the failure may degrade the performance of other devices, or even shut one or more (or even all) of them off entirely. One or more LEDs may fail during manufacture or operation due to a fault in, e.g., the LED die itself, one or more of the conductive traces supplying power to the LED, the substrate to which the LED is attached, or an electrical or mechanical connection between the LED contacts and the traces. While in some cases the failure of a single LED may be substantially imperceptible to an observer, the failure of one or more interconnected groups of LEDs (which, as mentioned above, may result from the failure of even a single LED) may result in a highly perceptible disruption in the illumination intensity and/or uniformity. Furthermore, replacement of faulty LEDs once integrated into a lighting system may be impractical. Thus, there is a need for methods of failure mitigation in illumination systems incorporating groups of interconnected discrete light sources such as LEDs.